Sorting Door Frequently Asked Questions
Why call it the "Sorting Door?"
What the Sorting Door does is to interrogate and evaluate RFID tags, to
make an educated guess about the person wearing or bearing those tags,
e.g., tags affixed to items of apparel, or embedded in an object like a
book. In some cases, the Door may be able to uniquely identify a person
(e.g., if it detects an object known to be possessed by a given
individual); in other cases, it may be able to put a person in one or more
categories, e.g., guess that the person is a petite female, based on
clothing size and style. (One could always fool the Sorting Door, of
course, or be mistakenly identified... the Sorting Door is as much art as
We're using a Door as a metaphor for the sorts of circumstances where
RFID surveillance may become common: given the relatively short ranges and
constrained environments (i.e., not too cluttered with other signals)
within which RFID will reliably work, putting RFID sensors in doorways, or
other physically-controlled spaces, would make the most sense.
(The name is also intended to evoke the Sorting Hat, from J.K.
Rowling's "Harry Potter." Placed on a student's head, the Sorting Hat
would interrogate the student's mind and character, to assign him or her
to a house; the Sorting Door will similarly interrogate individuals for --
to them -- intangible qualities, and render inferences as to their nature
What are RFIDs, and how prevalent are they?
RFID (radio-frequency identification) tags are small devices that can
be queried and read from a distance, using radio waves. The most
commonly-encountered RFID tags in the near to long-term future will likely
be so-called passive tags, bearing Electronic Product Code (EPC) numbers,
identifying items they're attached to--these tags are primarily what the
Sorting Door has been created to detect and assess.
While these RFID tags aren't very common today--the standards
for their creation and deployment have only just begun to be
disseminated--their potential future use raises policy (and privacy)
How can I tell if items I have have RFIDs in them?
It may not be easy--among other things, RFID tags are envisioned to act
as anti-theft devices, so easily-discovered RFID tags would defeat that
purpose. One can detect RFID tags with an RFID reader; the Sorting
Door is an RFID reader itself, and you can use it to find tags you might
If there are RFIDs on objects I own, should I worry?
RFIDs of the sort found on commercial products (i.e., Electronic
Product Code, or EPC, tags) allow for the unique identification of
products: beyond knowing what type, kind, shape, color, etc., of item,
each one bears a unique serial number. If you become associated with the
items you wear, carry, etc., it may be possible to monitor your
activities: the Sorting Door was conceived as a specific example of how
knowing things about things--being able to identify and track items--may
give clues to their owners' interests, habits, and activities.
What can I do about RFID tags I don't want?
RFID tags may be "killed" (i.e., turned off, permanently) or physically
removed. One might also be able to reprogram them, e.g., change their
original value to one that would be meaningless to the average